annex c: national electricity transmission system operator ...€¦ · annex c: national...

CVA Data Catalogue Version 26.0

Balancing and Settlement Code Page C-1 1 April 2020

© ELEXON Limited 2020

Annex C: National Electricity Transmission System Operator (NETSO)

EDL Specification

CONTENTS

1 INTRODUCTION ..................................................................................................................................... 3

1.1 PURPOSE AND SCOPE ............................................................................................................................... 6

1.2 DEFINITIONS ............................................................................................................................................ 6

1.3 RELATED DOCUMENTS ............................................................................................................................ 6

2 MESSAGE STRUCTURE DETAILS ...................................................................................................... 6

2.1 MESSAGE GUIDELINES - GENERAL DESCRIPTION .................................................................................... 6

2.2 MESSAGE PREFIX PART ........................................................................................................................... 8

Table 1. Message Prefix Part for MMS Input Mailbox ......................................................................... 8

Table 2. Message Prefix Part for MMS Output Mailbox ....................................................................... 8

Table 3. Message Prefix Part for CMS Output Mailbox ....................................................................... 8

2.3 MESSAGE HEADER PART ......................................................................................................................... 8

Table 4. Message Header Part .............................................................................................................. 8

Table 5. Message Header Categories ................................................................................................... 9

Table 6. Message Header Types ............................................................................................................ 9

Table 7. Message Header Instruction Types ......................................................................................... 9

Table 8. Message Header Error Flags ................................................................................................ 10

2.4 MESSAGE DATA PART ........................................................................................................................... 10

2.4.1 Control Messages .......................................................................................................................... 10

Table 9. Message Data Part for Control Messages ............................................................................ 10

Table 10. Control Error Messages ........................................................................................................ 11

Table 11. Message Data Part for Version Messages ............................................................................ 11

2.4.2 Instruction Messages ..................................................................................................................... 11

Table 12. Message Data Part for Status Change Instruction Messages ............................................... 12

Table 13. Message Data Part for BOA and Deemed Closed Instruction Messages .............................. 12

Table 14. Message Data Part for Change of Reason Code Instruction Messages ................................ 13

Table 15. Message Data Part for Voltage / MVAR Instruction Messages ............................................ 14

Table 16. Message Data Part for Pumped Storage Unit Instruction Messages .................................... 14

Table 17. Instruction Message Error Codes ......................................................................................... 16

2.4.3 Submission Messages .................................................................................................................... 16

Table 18. Message Data Part for Submission Messages ....................................................................... 16

Table 19. Message Data Part Variations for MEL/MIL Submission Messages .................................... 17

Table 20. Message Data Part variations for RUR/RDR Export/Import Submissions ........................... 17

Table 21. Message Data Part variations for Single Time Value Parameter Submissions .................... 17

Table 22. Message Data Part Variations for SEL/SIL Submission Messages ....................................... 18

Table 23. Message Data Part for variations for Maximum Delivery Submission Messages ................ 18

2.4.4 Submission Error codes ................................................................................................................ 18




Table 24. Submission Error Codes ........................................................................................................ 18

2.5 UNDELIVERED MESSAGES ..................................................................................................................... 18

2.6 ALARM MESSAGES ................................................................................................................................ 19

Table 25. Alarm codes for CMS Alarm Mailbox ................................................................................... 19

Table 26. CMS Alarm Codes ................................................................................................................. 19

Table 27. Alarm codes for the MMS Alarm Mailbox............................................................................. 19

Table 28. MMS Alarm Codes ................................................................................................................ 19




1 Introduction

Electronic Dispatch Logging was the principal mechanism by which power stations in

the Pool received instructions from the National Electricity Transmission System

Operator (NETSO) and redeclared availability and dynamic parameters to the NETSO.

Under NETA within the rolling Balancing Mechanism window, the balancing of the

power system is the NETSO’s sole responsibility. A secure, reliable and proven

system for issue and acceptance of balancing instructions is a pre-requisite for the

NETSO prior to first operation of the power system under NETA. The EDL approach

has been adopted for NETA as it is familiar to many and therefore represents a low

risk to the NETA programme against the target implementation date.

EDL is the means by which a Control Point for a single or number of BMUs

communicates with the NETSO. Any Control Point who wishes to receive balancing

market instructions and Ancillary Services instructions from the NETSO under NETA

must have an EDL link to the NETSO. An overview of the interfaces with the

NETSO under NETA was given in a DISG paper 19/01.

Logically the EDL system comprises four layers; Application, Communication, Server

and Wide-area Network as illustrated in Figure 1.

Application Layer. This contains the Man-Machine User Interface and other

supporting processes. This layer is provided entirely by each of the NETSO and

the Company responsible for the Control Point to meet their own individual

requirements.

Communication Layer1. This provides the interface between the application layer

(often via a database) and the server layer (via messages). It is primarily the

Communications Layer which implements the interface described in this

document. This layer is provided by each of the NETSO and the Company

responsible for the Control Point to meet both their own individual requirements

and the functional requirements of the EDL Server Layer.

Server Layer. This is that part of the Wide-area Network Layer which transfers

data between origins and destinations within a network-server domain

(transparent task to task communication) to provide the message delivery system.

This layer is provided by the NETSO.

Wide-area Network layer. For present purposes, this may be taken to include the

lower layers (i.e. physical and data link layers) of the required communications

stack. It may be TCP/IP (the NETSO’s preferred option) provided by any

platform vendor or DECnet provided by Compaq.

1 Not to be confused with the seven Communications Layers of the ISO OSI Model




Figure 1. Process Layers in EDL System




The logical implementation of the layer strategy is illustrated in Figure 2. The interface

between the Communications Layer and the Server Layer is via messages deposited in four

inter-process communications queues. It is the format of these messages that is the subject of

this document.

Figure 2. Diagram of EDL Processes

The Server Layer consists of a single process on each node. The Master Message Server

(MMS) runs on the System Operator (NETSO) node and establishes connections to a

Client Message Server (CMS) on each Control Point node.




1.1 Purpose and Scope

This document defines the structure and content of EDL instruction and submission

messages that are required to implement Phase 1 of the NETA project.

1.2 Definitions

BMU Balancing Mechanism Unit

BOA Bid Offer Acceptance

EDL Electronic Dispatch Logging – A message transfer mechanism

MEL Maximum Export Limit

MIL Maximum Import Limit

MNZT Minimum Non-Zero Time

MZT Minimum Zero Time

NDZ Notice to Deviate from Zero

NETA New Electricity Trading Arrangements

NTB Notice to Deliver Bids

NTO Notice to Deliver Offers

RDR Run-down Rates

RUR Run-up Rates

SEL Stable Export Limit

SIL Stable Import Limit

1.3 Related Documents

1. NETA – A Draft Specification for the Balancing Mechanism and Imbalance

Settlement, Version 1.2, July 1999, The Office of Gas and Electricity Markets.

2. NETA – Data Validation, Consistency and Defaulting Rules, CT/24.12.0003.

2 Message Structure Details

2.1 Message Guidelines - General Description

All messages are simple ASCII text strings to aid development of Application and

Communication layers by all parties. With the exception of Server Messages the

messages comprise three parts.

A message Prefix Part

A message Header Part

A message Data Part

The message Prefix Part is not transmitted between computer systems. It is used for

communication between the Communications Layers and the Server Layers of the

system on each node.

Message Prefix Parts are removed by the Server Layer from messages received from

the Communication Layer before sending the messages to the Wide-area Network

Layer for transmission.

Messages Prefix Parts are added by the Server Layer to messages received from the

Wide-area Network Layer before sending the messages to the Communication Layer.




The message Header Part is constructed by the Communication Layers.

The message Data Part is constructed by the Communication Layer, usually based on

information from the Application Layer, although some messages are originated by the

Communications Layer.

This separation between Header & Data Parts is notional. In practice some elements of

the Data Part will be processed by the Communications Layers. Furthermore the

boundary between Header and Data Parts has been deliberately constructed such that

the common components of all messages are arranged at the beginning of the Data

Part and so may be viewed as either Header or Data Parts.

All dates and times2 are referenced to Greenwich Mean Time.

Times stamps within message Data Parts are to a resolution of one minute. The

standard DEC-VMS format is used. i.e. dd-mmm-yyyy hh:mm. (17 characters). Note

that the valid range of the time component is 00:00 to 23:59.

Time stamps within message prefix parts are to a resolution of 10ms. The standard

DEC-VMS format is used. i.e. dd-mmm-yyyy hh:mm:ss.nn. (23 characters). Note that

the valid range of the time component is 00:00:00.00 to 23:59:59.99.

Fields within the Prefix Parts and the Data Parts are delimited by a space character. All

message parts are terminated with a ^ character.

Fields containing variable length text items are left justified and space filled.

Fields containing variable length numeric items are right justified and zero filled.

The leading character of the day part of a date/time field may be a space.

Messages consist of three types; control, instruction and submission. Select/deselect

control messages are sent from the NETSO to a Control Point while path/nopath

control messages are sent from a Control Point to the NETSO. These messages

control the availability of a BM Unit both to be instructed by the NETSO and to

submit dynamic parameters. For instruction and submission messages to be

exchanged, the NETSO must first have sent a select message while the Control Point

must have sent a path message. Various message formats are defined for Ancillary

Service instructions and Balancing Market Bid/Offer Acceptance instructions that are

used by the NETSO to instruct a Control Point. Likewise, submission message

formats are defined which allow a Control Point to submit various BM Unit dynamic

parameters to the NETSO. If an error is detected by the Control Point in an instruction

message, or by the NETSO in a submission message, the text of the message, or the

truncated part thereof containing a reference number and log time will be sent back to

the originator together with a pre-defined error code.

2 Inter-machine time comparisons should only be to a minute resolution




2.2 Message Prefix Part

The message Prefix Part is different for each mailbox between the Communication

Layer and the Server Layer. There is no Prefix Part on messages from the

Communication Layer to the Server Layer on the station node, i.e. on messages in the

CMS input mailbox.

Table 1. Message Prefix Part for MMS Input Mailbox

Field Name Start

Position

Field

Size

Description

Destination 1 6 Name of Control Point

Terminator 7 1 Part terminator character "^"

Table 2. Message Prefix Part for MMS Output Mailbox

Field Name Start

Position

Field

Size

Description

Destination 1 6 Name of Control Point

Time-Stamp 8 23 Time message received from Wide-area Network.

Obtained from local node system clock.


Table 3. Message Prefix Part for CMS Output Mailbox

Field Name Start

Position

Field

Size

Description

Time-Stamp 1 23 Time message received from Wide-area Network.

Obtained from local node system clock.


2.3 Message Header Part

The message Header Part is a packed string of four characters followed by a terminator. The character

positions and sizes of the various fields are described in Table 4.

Table 4. Message Header Part

Field Name Start

Position

Field

Size

Description

Category 1 1 The category of message. Instruction, Submission etc.

See Table 5

Type 2 1 The type of the message. This field carries the dialogue

between Communication Layers.

See Table 6 for details.

Instruction

Type

3 1 NOTE: This field is only used for Instruction Category

Messages and is a space for all other Categories of

message

See Table 7 for Details.

Error 4 1 Flag set to space by originating process. The message

may be returned with the flag set. See 0 for details.





Each transaction dialogue between Communication Layers consists of a single new

outgoing message followed by one or more returned messages. Return messages are

referenced to the original message and have return message types as shown in Table 6

They also retain the Message Category and Instruction Type of the original message.

Table 5. Message Header Categories

Category Description

C Control Messages. See Table 9 for Data Part details

I Instruction Messages. See Table 12, Table 13, Table 14, Table 15 and Table 16 for

Data Part details

R Submission Messages. See Table 18 for Data Part Details

Table 6. Message Header Types

Code Mnemonic Direction Meaning

N New Send A new (real-time) message.

W Waiting Return The remote Communications Layer has received &

validated the referenced message. It is now waiting

for manual action. This type is often called

Technical Acknowledgement in earlier papers.

U User

Acknowledgement

s

Return The remote operator has seen the referenced

message.

A Acceptance Return The remote operator accepts the referenced

message.

R Reject Return The remote operator rejects the referenced message.

T Telephoned Send Upon re-connection of systems, messages that have

been transmitted by telephone are sent

electronically to allow the systems to reconcile

themselves.

D Dispute Return The remote system cannot reconcile a manually

entered transaction.

Table 7. Message Header Instruction Types

Instruction

Type Code

Meaning

Space Control Message, Submission Message, or EDL closed instruction messages.

See Table 9, Table 12, Table 13, Table 14 and Table 18 for Data Part details

V EDL Voltage Control Instruction.

See Table 15 for Data Part details.

P Pumped Storage Message. See Table 16 for details




Table 8. Message Header Error Flags

Error Flag Meaning

Space Original message

E An error is detected in a received message. Either the original message is returned

to the originator with a four-character error code appended to it or a new message

identifying the reference number of the original message together with a 4-

character error code is sent to the originator. The error code may relate to the

syntax or data consistency of the message

X A message is returned to the originator. The message was valid and data consistent

when first received, but while waiting for a user acknowledgement, other

parameters have changed and the message is no longer consistent. It is thus flagged

as expired i.e. a valid message that is no longer meaningful.

2.4 Message Data Part

The content of the Message Data Part depends primarily on the Message Category and

secondarily on the Message Type. In the case of Instruction Category Messages the

Instruction Type also influences the Message Data Part. Single space characters to

further enhance the readability of the messages separate fields within the Message

Data Parts. The Message Data Parts for each category are defined in the following

tables.

2.4.1 Control Messages

The Message Data Part for control messages is a maximum of 56 characters. The

length and contents of control messages depends on the nature of the message, the

options are detailed in Table 9.

Table 9. Message Data Part for Control Messages

Field Name Start

Position

Field

Size

Description Valid

Type

Error

Flag

Name 1 9 Control Point Name (VERSON

message only) or BM Unit Name

All

Ref Number 11 10 Message Reference Number All

Log Time 22 17 Time message logged by

originating process

All

Type 40 6 Specifies the type of control

message and the structure of the

type dependent message part.

N

Type

dependant

Type Details

VERSON See Table 11

SELECT The Control Point is

selected by the

NETSO for EDL.

DESEL The Control Point is

de-selected by the

NETSO for EDL

PATH There is a path from

the Control Point

Communication

Layer to the BM

Unit operator.




Field Name Start

Position

Field

Size

Description Valid

Type

Error

Flag

NOPATH There is NO path

from the station

Communication

Layer to the BM

Unit operator

Error Code 40, 47 or

52

4 See Table 10 for meaning Any E

Terminator 44, 39, 46,

51, or 56

1 Part terminator character "^" All

Dispatch Instructions to an individual BM Unit via EDL will only take place once a

PATH message from the control point, and a SELECT message from the NETSO have

been sent. All other states will result in Instructions being issued by voice telephone.

Table 10. Control Error Messages

Error Code Description

C001 Invalid Control Point/BM Unit ID

C002 Invalid Control Type

C003 Unsupported Version Number

C004 Message arrived before VERSION accept

Submission and Control Messages can be issued at any time, irrespective of select and

path states.

Table 11. Message Data Part for Version Messages

Field Name Start

Position

Field Size Description

Type 40 6 VERSON

Version 47 4 Latest Supported EDL Interface Definition.

The field is a formatted numeric value. e.g. 0021 to

specify version 2.1. The version number is

changeable and reflects the current level of

messages supported at the NETSO and the Control

Point.

2.4.2 Instruction Messages

2.4.2.1 Status Change Instruction Messages

The message Data Part for Status Change instruction messages is a maximum of 104

characters.

Note that Status Change instructions are to be issued for Ancillary Service purposes to

change the operating state of a BM Unit, for example perhaps to instruct a Unit to

synch to the declared FPN, or to instruct a Unit off. If a MW output level is to be

instructed, a Bid/Offer Acceptance closed instruction must be issued.




Table 12. Message Data Part for Status Change Instruction Messages

Field Name Start

Position

Field

Size

Description Valid

Type

Error

Flag

Name 1 9 BM Unit Name All

Ref Number 11 10 Instruction Reference Number All

Log Time 22 17 Time message logged by originating

process

All

Start

Instruction

Code

40 5 This may be one of the following

codes SYN, HTS or the numeric value

0.

N, T

Start Reserve 46 3 Not used. N, T

Start Time 50 17 Start time of the instruction. N, T

Reason Code 68 3 Three character reason code applied to

steam plant; the first character explains

why the instruction was issued, the

second character indicates whether the

BM Unit is in frequency response

mode.

N,T

Target

Instruction

Code

72 5 This may be one of the following

codes OFF, HTS, CHS or the numeric

value 0.

N, T

Target

Reserve

78 3 Not used. N, T

Target Time 82 17 Target time of the instruction. N, T

Error Code 40, 100 4 See Table 17 for meaning Any E, X

Terminator 39, 44, 99

or 104


Participants and Vendors should contact the NETSO for an up-to-date list of reason

codes and an accompanying explanation.

2.4.2.2 Bid / Offer Acceptance and Deemed Closed Instruction Message

The message Data Part for a closed instruction is a maximum of 183 characters in

length. A closed instruction will be sent to accept either BM Unit Bids or BM Unit

Offers. The closed instruction must contain at least two MW / time value pairs up to a

maximum of five value pairs that describe a closed volume of energy (in conjunction

with the physical notification and any relevant previously accepted BOAs).

Table 13. Message Data Part for BOA and Deemed Closed Instruction Messages

Field Name Start

Position

Field

Size

Description Valid

Type

Error

Flag




originating process

All

Type 40 4 Type of instruction. BOAI or

DEEM.

N, T

BOA

Number

45 10 BM Unit Bid/Offer Acceptance

Number

N, T

Number of

Data Points

56 2 Count of the number of MW /

Time pairs that make up this

closed instruction. There must

be a minimum of 2 pairs and a

maximum of 5.

N, T




Field Name Start

Position

Field

Size

Description Valid

Type

Error

Flag

MW1 59 5 MW

Value 1 nnnn N,T

T1 65 17 Time

value 1

MW2 83 5 MW

Value 2

Error code A

N, T

T2 89 17 Time

value 2

MW3 107 5 MW

Value 3

Optional MW /

Time pair 3;

Error code B

N, T

T3 113 17 Time

value 3

MW4 131 5 MW

Value 4

Optional MW /

Time pair 4;

Error code C

N, T

T4 137 17 Time

value 4

MW5 155 5 MW

Value 5

Optional MW /

Time pair 5;

Error code D

N, T

T5 161 17 Time

value 5

Error Code 40,

107 A,

131 B,

155 C,

179 D

4 See Table 17 for meaning Any E, X

Terminator 39, 44,

106, 111,

130, 135,

154, 159

178, 183


2.4.2.3 Reason Code Instruction Messages

The message Data Part for a reason code instruction message is a maximum of 71

characters. This instruction sets the current reason code for a BM Unit. It is used, for

example, to instruct a BM Unit’s frequency response.

Table 14. Message Data Part for Change of Reason Code Instruction Messages

Field Name Start

Position

Field

Size

Description Valid

Type

Error

Flag




process

All

Type 40 4 Type of instruction. REAS N, T

Reason Code 45 3 Three character reason code. N, T

Start Time 49 17 Start time of the instruction. N, T



or 71


Participants and Vendors should contact the NETSO for an up-to-date list of reason

codes and an accompanying explanation.




2.4.2.4 Voltage / MVAR Instruction Messages

The message Data Part for Voltage Instruction messages is a maximum of 73

characters. All voltage control instructions are supported by EDL level 2 (VERSON

0020).

Table 15. Message Data Part for Voltage / MVAR Instruction Messages

Field Name Start

Position

Field

Size

Description Valid

Type

Error

Flag




originating process

All

Type 40 4 Type of instruction. MVAR or

VOLT

N, T

Value 45 4 Target value as a whole number

preceded by minus ("-" = negative

value), plus ("+" = positive value),

or space (" " = positive value) and

with 3 digits (i.e. leading zero's

always supplied).

Note: + zero & - zero are treated

as same instruction

N, T

Target Time 50 17 Target time of the MVAR or

VOLT instruction.

N, T



or 72


2.4.2.5 Pumped Storage Instruction Messages

For Pumped Storage plant, currently Dinorwig and Ffestiniog stations, MW loading

and pump instructions will use the closed instruction format given in Table 13.

The following message format will be used to set a pumped storage unit’s:

current reason code

droop value

low frequency relay value

current operating state

Voltage instruction messages will be in the standard format as described in Table 15.

Table 16. Message Data Part for Pumped Storage Unit Instruction Messages

Field Name Start

Position

Field

Size

Description Valid

Type

Error

Flag

Name 1 9 Pumped Storage Unit Name All



process

All

Reason Code 40 4 Four character reason code, (see below

for more detail)

N, T

Start Time 45 17 Start time of instruction. N, T




Field Name Start

Position

Field

Size

Description Valid

Type

Error

Flag

Target 63 5 Depending on the reason code: a

mnemonic or a real value (see below

for more detail).

N, T

Target Time 69 17 Target time of the instruction. N, T

Error Code 87 4 See Table 17 for meaning Any E, X

Terminator 92 1 Part terminator character "^" All

Reason Codes can be one of the following

Reason

Code

Description

LFSM Limited Frequency Sensitive Mode

PSHF Carry Primary, Secondary and High Frequency Response

EMRG Emergency instruction (instruction to operate outside declared parameters)

FRES Fast Response Required

LFRY Instruction to set an Low Frequency relay

DROP Droop instruction

BKDN Breakdown

Target Field can be one of the following

Target Description

MW Reason code to be applied to the Pumped Storage BOA Closed Instruction

SH Shutdown

SG Spin Gen

SP Spin Pump

Nn.nn Set low frequency relay to nn.nn Hz. For example nn.nn could be 49.85. Where nn.nn

is sent as 00.00 this should be interpreted as remove LF relay setting .

n.n Set droop to n.n %

Truth table

MW positive output SH SG SP MW negative output nn.nn n.n

LFSM x x x x x

PSHF x x

EMRG x x x x x

FRES x

LFRY x

DROP x

BKDN x




2.4.2.6 Instruction Message Error Codes

The error codes in Table 17 can be used with instruction messages.

Table 17. Instruction Message Error Codes


I001 Invalid BM Unit ID

I002 Invalid Reference Number (Current reference Last reference, or no previous

reference to instruction with this number)

I003 General instruction syntax error (instruction parsing failed)

I004 Instruction received for a BM Unit with NO PATH

I005 Instruction received before Version Control Procedure completed

I006 Telephoned Instruction received with an Invalid Reference Number.

I007 Attempt to recover previously rejected instruction

I008 Unable to log instruction

I009 Invalid Telegraph Instruction Number

I010 Attempt to Reject Reconciliation Instruction which has already been sent to

Settlements

2.4.3 Submission Messages

Submission messages conform to the message structure and error checking detailed in

Reference 2. The structure of the Data Part depends on the parameters being

re-declared, the options are detailed in Table 18.

The message Data Part for Submission messages is a maximum of 107 characters.

Table 18. Message Data Part for Submission Messages

Field Name Start

Position

Field

Size

Description Valid

Type

Error

Flag


Ref Number 11 10 Submission Reference Number All


originating process

All

Type 40 6 Specifies the type of Submission

and the structure of the type

dependent message part.

N, T

Type

Dependent

47 Max 57 Type Details N, T

MEL, MIL

(error code A)

Table 19

RURE, RURI,

RDRE, RDRI

(error code B)

Table 20

NDZ, NTO, NTB,

MZT, MNZT

(error code C)

Table 21

SEL, SIL

(error code D)

Table 22

MDVP

(error code E)

Table 23

Error Code 40 any, 4 Not used. Any E, X




Field Name Start

Position

Field

Size

Description Valid

Type

Error

Flag

103 (A),

79 (B),

51 (C),

57 (D),

61 (E)

Terminator 39, 44

102, 107,

78, 83,

50, 55,

56, 61,

60, 65


Table 19. Message Data Part Variations for MEL/MIL Submission Messages

Field Name Start Position Field Size Description

Type 40 6 “MEL” or “MIL” keyword

Time from 47 17 Start time

MW from 65 9 MW at time from (nnnnnnnn)

Time to 75 17 End time

MW to 93 9 MW at time to (nnnnnnnn)

Table 20. Message Data Part variations for RUR/RDR Export/Import

Submissions

Submission messages for RUR/RDR parameters contain fields that are optional.

Unused fields are treated as null values. Null values are specified by filling the field

with ‘*’ characters. The three valid combinations of parameters and nulls are

identified in 0.

Field Name Start

Position

Field

Size

Description

Type 40 6 “RURE”,

“RURI”,

“RDRE”, or

“RDRI”

keywords

Valid Combinations

Rate 1 47 6 First Rate

Elbow 2 54 5 Optional Second

Elbow (nnnn)

*****

Rate 2 60 6 Optional Second

Rate ******

Elbow 3 67 5 Optional Third

Elbow (nnnn) ***** *****

Rate 3 73 6 Optional Third

Rate ****** ******

Table 21. Message Data Part variations for Single Time Value Parameter

Submissions

Field Name Start

Position

Field

Size

Description

Type 40 6 “NDZ”, “NTO”, “NTB”, “MZT” or “MNZT

keyword

Time value 47 3 Number of minutes




Table 22. Message Data Part Variations for SEL/SIL Submission Messages


Type 40 6 “SEL” or “SIL” keyword

Value 47 9 MW level

Table 23. Message Data Part for variations for Maximum Delivery Submission

Messages


Type 40 6 “MDVP” keyword

MDV 47 11 Max Delivery Volume (MW hours)

MDP 59 3 Max. Delivery Period (minutes)

2.4.4 Submission Error codes

A submission message is automatically acknowledged by the NETSO using a message

with the message Header Part “RW ^”.

The submission undergoes syntax and validation checking. If the submission is valid,

the return message with the message Header Part “RU ^” is sent to the Control Point;

otherwise, if an error is encountered, a message with the message header part “RN E”

is sent with a reason code appended.

Table 24. Submission Error Codes


R001 Invalid syntax

R002 Invalid BM Unit

R003 Value out of bounds

R004 Invalid run rate break point

R005 Invalid run rate

R006 Invalid combination of run rates/breakpoints

R007 Invalid run rate breakpoint; breakpoints not monotonically increasing

R008 FROM time does not predate TO time

R009 Invalid FROM time

R010 Invalid TO time

R011 FROM time must be equal to or after SUBMISSION time

R999 Contact the NETSO

2.5 Undelivered Messages

There will be rare occasions when messages will not be acknowledged as successfully

transferred from the Communications Layer on one node to the Communications

Layer on another node. This may be due to

the message was not transferred – communications failure

the remote message server failed to acknowledge receipt of the successfully

delivered message.

All such messages which cannot be delivered to the remote partner are deposited in the

undelivered mailbox on the sending node. Any message Prefix Part in the input




mailbox is also echoed to the undelivered mailbox. The Communications Layer must

monitor this mailbox, and possibly re-present the message when connection is re-

established.

2.6 Alarm Messages

The Server Layer continuously monitors the Wide-area Network Layer. Whenever a

connection with a remote partner changes, a message is deposited in the Alarm

mailbox.

Table 25. Alarm codes for CMS Alarm Mailbox

Field Name Start

Position

Field

Size

Description

Code 1 3 See 0

Time Stamp 5 23 Time alarm raised by Server Layer, obtained

from local node system clock.

Table 26. CMS Alarm Codes

Alarm Meaning

IC Input channel connected

OC Output channel connected

ID Input channel disconnected

OD Output channel disconnected

NX Network Partner Exited

Table 27. Alarm codes for the MMS Alarm Mailbox

Field Name Start

Position

Field

Size

Description

Destination 1 6 Name of BM Unit

Code 8 6 See 0

Time Stamp 15 23 Time alarm raised by Server Layer, obtained

from local node system clock.

Table 28. MMS Alarm Codes

Alarm Meaning

C-P Primary Channel Connected

C-S Secondary Channel Connected

D-P Primary Channel Disconnected

D-P(R) Primary Channel disconnected due to a link re-configuration

D-S(R) Secondary Channel disconnected due to a link re-configuration

D-P(U) Primary Channel disconnected due to a message being

undelivered/unacknowledged

D-S(U) Secondary Channel disconnected due to a message being

undelivered/unacknowledged

D-S Secondary Channel Disconnected

NX Network Partner Exited